Abstract: “A large drainage-tunnel with an inside diameter of 5 m will be constructed in Bangkok using tunnel boring machines (TBM) by the end of 2018. One of the most challenging problems in this operation is how to determine the number of supply trains containing muck cars for the muck evacuation process during the boring. This paper presents an optimization of the number of the supply trains employed in the project so that the operation of the train fleet will be well synchronized with that of the TBM. Petri Net-based models and their simulation are used as the means for the optimization. The COSMOS simulator, which is reliable software for running Pet Net-based models, is used for the simulation. The simulation results indicate that the optimal numbers of supply trains are 2, 3, 4 and 5 for the tunnel lengths of 0-0.9, 0.9-2.7, 2.7-4.5 and 4.5-5.5 km, respectively. The analysis of these results also offers the numbers and the locations of the double track positions for each interval of the tu”

Keywords: optimization, simulation, model, operation, tunnel, boring, supply train, TBM